🏷️ Basic Information

Make:

BMW

Model:

525i

Year:

1990

Chassis Code:

E34

Engine Code:

M50B25

👋 Introduction

Segment:

Executive Sedan (Mid-size luxury)

Competitors:

Mercedes-Benz E-Class (W124), Audi 100/200, Lexus ES 250, Jaguar XJ (XJ40).

Design:

Iconic E34 design by Claus Luthe, distinguished by its clean lines, Hofmeister kink, and double kidney grille. Known for aerodynamic efficiency and classic BMW proportions.

Powertrain:

Smooth and potent M50B25 inline-six engine, refined chassis, rear-wheel drive (RWD) bias, optional limited-slip differential (LSD).

Interior:

Driver-focused cockpit, high-quality materials, ergonomic seating, excellent build quality.

Value:

Offers a blend of performance, luxury, and enduring build quality, making it a desirable classic car that can be maintained to a high standard with the right documentation.

📋 Manual Details

Coverage:

Full Service Repair

Pages:

Extensive (Exact count not specified, but implied to be comprehensive)

Type:

Service and Repair Manual

Language:

English (Assumed based on product description phrasing)

Format:

Digital (Likely PDF, based on typical sales of such manuals)

📖 Manual Coverage

Engine:

Complete overhaul, diagnostics, tuning, fuel injection, ignition system, cooling system, exhaust system, lubrication system.

Transmission:

Manual and automatic transmission repair, overhaul, fluid service, diagnostics, driveline components.

Brakes:

Hydraulic system, ABS system, disc brake service, drum brake service (if applicable), parking brake, fluid specifications, bleeding procedures.

Electrical:

Complete wiring diagrams, component testing, diagnostic procedures for engine control, body electronics, lighting, instruments, power accessories.

Suspension Steering:

Front and rear suspension component replacement, alignment specifications, steering system diagnosis and repair, power steering.

Body Chassis:

Body panel repair, rust prevention, door mechanisms, glass replacement, interior trim, chassis component inspection and replacement.

HVAC:

Air conditioning system service, heater core replacement, blower motor, climate control diagnostics.

Maintenance:

Scheduled maintenance intervals, oil changes, filter replacements, spark plug service, belt inspection and replacement, fluid level checks and top-offs.

Repair:

Detailed step-by-step repair instructions for all major vehicle systems, including engine rebuilding, transmission overhauls, and electrical component replacement.

Diagnostics:

Troubleshooting guides, diagnostic flowcharts, symptom-based problem resolution, interpretation of diagnostic trouble codes (DTCs) if applicable to the era's systems.

Rebuilding:

Comprehensive instructions for rebuilding major components like the engine, transmission, and differential.

Refurbishment Restoration:

Guidance on refurbishing and restoring various parts of the vehicle, including bodywork, interior, and mechanical components.

Depth:

Expert-level. Covers everything from basic fluid changes to complete engine and transmission rebuilds, including in-depth electrical diagnostics and schematics.

📊 Manual Specifications

Format:

PDF (Likely, with searchable text and high-resolution diagrams)

Quality:

High Resolution (Expected for clear diagrams and text)

Binding:

N/A (Digital Format)

Paper:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Type:

Naturally Aspirated Inline-6 Cylinder

Displacement:

2494 cc (2.5 Liters)

Bore X Stroke:

84.0 mm x 90.0 mm

Compression Ratio:

8.8:1

Valvetrain:

DOHC (Dual Overhead Camshafts), 4 valves per cylinder (24 valves total)

Horsepower:

168 hp @ 5500 rpm (DIN)

Torque:

226 Nm (167 lb-ft) @ 4300 rpm (DIN)

Fuel Delivery:

Bosch Motronic Electronic Fuel Injection (EFI)

Fuel Type:

Unleaded Gasoline (Premium recommended)

System:

Electronic Ignition with Knock Sensor Control

Oil Capacity:

6.5 Liters (6.9 US Quarts) with filter change

Coolant Capacity:

10.0 Liters (10.6 US Quarts)

🔧 Transmission

Type:

5-Speed Manual Transmission (Getrag 260/5)

Type:

4-Speed Automatic Transmission (ZF 4HP-22)

Driveline:

Rear-Wheel Drive (RWD)

Differential:

Open Differential (Optional Limited-Slip Differential - LSD)

Manual Fluid:

BMW ATF Dexron II (or equivalent)

Automatic Fluid:

BMW ATF Dexron II (or equivalent)

📐 Dimensions

Length:

4720 mm (185.8 inches)

Width:

1751 mm (68.9 inches)

Height:

1410 mm (55.5 inches)

Wheelbase:

2760 mm (108.7 inches)

Curb Weight:

1540 kg (3395 lbs) (Approximate, varies with transmission and options)

Gross Vehicle Weight:

2000 kg (4409 lbs) (Approximate)

Trunk Volume:

460 Liters (16.2 cubic feet)

🛡️ Safety Features

NHTSA Driver Front Impact:

Not explicitly rated by modern NHTSA standards, but generally considered robust for its era.

IIHS Side Impact:

Not explicitly rated by modern IIHS standards, but generally considered robust for its era.

ABS:

Standard Anti-lock Braking System (ABS)

Airbags:

Driver-side airbag standard on 1990 models. Passenger airbag optional or standard on later E34 iterations of this year.

Seatbelts:

3-point inertia-reel seatbelts with pretensioners (front seats).

Chassis Structure:

Reinforced safety cell, crumple zones front and rear for energy absorption.

💡 Technology Features

Audio System:

BMW Bavaria C (Cassette player) or similar era premium audio systems with optional CD changer integration.

Display:

Simple dot-matrix displays for OBC (On-Board Computer) and climate control.

Cruise Control:

Standard or Optional electronic cruise control system.

Phone Integration:

Not applicable for modern connectivity; early optional car phone integration may exist.

🔧 Maintenance

Oil Change Interval:

Every 7,500-10,000 miles (12,000-16,000 km) or annually, depending on driving conditions and oil quality.

Spark Plug Replacement:

Typically around 30,000 miles (48,000 km) for original plugs; consult manual for specific plug type and interval.

Coolant Flush:

Every 2-3 years or 30,000-50,000 miles (48,000-80,000 km).

Transmission Fluid Change:

Manual: Every 50,000-75,000 miles (80,000-120,000 km). Automatic: Every 30,000-50,000 miles (48,000-80,000 km) or as per manual, though often considered 'lifetime' by some, replacement is recommended.

Engine Oil:

SAE 15W-40 or 15W-50 API SG/SH (Check owner's manual for precise BMW approval specifications)

Coolant:

Ethylene Glycol based coolant with corrosion inhibitors (typically 50/50 mix with distilled water).

Brake Fluid:

DOT 3 or DOT 4

Oil Leaks:

Common valve cover gasket leaks, oil pan gasket leaks, and rear main seal leaks over time.

Cooling System:

Plastic coolant expansion tank can become brittle and crack. Water pump failure can occur.

Electrical:

ABS sensor failures, instrument cluster illumination issues, wiring harness degradation (especially in the engine bay).

Suspension:

Worn control arm bushings, worn ball joints, and aging shock absorbers are common wear items.

Fuel System:

Fuel pump and fuel pressure regulator can fail with age. Injector seals can leak.

Filters:

Mann-Filter or Mahle for oil, air, and fuel filters are highly recommended for quality and fitment.

Spark Plugs:

Bosch or NGK Platinum or Iridium plugs are suitable for this M50 engine.

📚 Vehicle History

Bmw Legacy:

BMW's reputation for building sporty, driver-focused luxury sedans with excellent engineering and performance.

E34 Introduction:

The E34 generation of the 5 Series was introduced in 1987 (Europe) and 1988 (North America). The 525i, featuring the new M50 engine, replaced the 525i with the M20 engine for the 1990 model year in North America.

Engine Transition:

The M50 engine was a significant upgrade, featuring a dual-camshaft design and DOHC, providing more power and smoother operation than the previous M20 engine.

Production Years:

E34 5 Series: 1987-1995. Specifically, the 525i with the M50 engine was produced from late 1989 through 1995.

Plant:

Dingolfing, Germany

🏆 Awards & Recognition

Car And Driver 10Best:

The E34 generation (including the 525i) was a frequent recipient of Car and Driver's 10Best list during its production run, acknowledging its superior driving dynamics and build quality for the era.

Overall Reputation:

Widely regarded as one of the best driving sedans of its time, a benchmark for handling, comfort, and build quality in the luxury segment.